The invention seeks to satisfy the need for a more precise and reliable positive positioning means for workpieces held on tables of machine tools, such as milling machines, jig bores, grinders, etc. In the prior art, various workholders and positioners have been devised to meet particular needs. In many cases, the prior art devices are complex and unduly costly and have to be customized to satisfy particular machining operations. Therefore, they lack the flexibility necessary for repeated or wide usage in machining operations and are frequently inconvenient to set up on a machine tool table, such as the table of a milling machine. Some examples of the known prior art are contained in the following U.S. Pat. Nos. which are made of record herein to satisfy the requirements for disclosure under 37 C.F.R. 1.56:
521,802 1,914,542 PA1 882,943 3,124,180 PA1 1,234,176 3,704,880